Providing fluid flow through a conduit is a common requirement. In industrial applications, the flow of air, water or other fluids is often required in the operation of equipment. In residential settings, household plumbing is probably the most common example of fluid flow in a conduit. In these applications, it is often desirable to have the ability to control the flow of fluid at one or more points, through the use of shut-off valves. Such valves can be used simply as an outlet for the fluid, or to isolate downstream elements for such purposes as repair or maintenance.
The conduits to which a valve is to be connected will have a particular configuration defined by the conduit material, size, type of end connections, and arrangement.
Typical conduit materials include copper, plastic, rubber, steel, and composites.
The size of the conduit is generally specified by the inner diameter, but the outer diameter may also be important in certain connection types.
There are a wide variety of end connection types, including socket ends for soldering, male and female thread connections, compression fittings, barb fittings, flare connections, and many others.
The arrangement of the conduit refers to the number and orientation of the conduits to which the valve is to be connected. The arrangement may include a single conduit, at the end of which the valve is to be installed. Alternatively, the arrangement may include two coaxial conduits, requiring a straight valve, or two perpendicular conduits, requiring an angle valve. The arrangement could also consist of three conduits for which a “T” valve is required.
It is readily apparent that the number of unique conduit configurations is considerable. Stocking a comprehensive inventory of valves is therefore a difficult and costly task. For plumbers or pipefitters, it is generally cost prohibitive to carry a large inventory. Plumbers may have sources from which specific valves can be ordered, but receiving the valve is of course delayed by processing and delivery time. Alternatively, plumbers may have access to wholesale suppliers but such suppliers are not usually open in evenings or on weekends. As a result this may cause considerable delay and inconvenience.
The do-it-yourself homeowner will generally not stock any parts. Rather, he or she will typically rely on local hardware or home improvement retailers. These stores are usually open in evenings and on weekends, which is particularly convenient for the do-it-yourself homeowner. However, these retailers are also reluctant to incur the high cost of inventory associated with stocking ready-to-use valves in numerous variety, or to give up the large amount of shelf space which such a variety of valves would require.
It would be advantageous to have a kit of parts from which a valve could be assembled. Such a kit for assembling a valve is disclosed in U.S. Pat. No. 5,735,307 to Charron. The kit includes a valve body and end connectors which fit between the valve body and the conduits to which the valve is to be connected.
However, the valve assembled according to the '307 patent is assembled in a production environment by the manufacturer. The manufacturer therefore achieves inventory cost reductions and convenience by following the teaching of the patent, but such benefits are not experienced by plumbers or do-it-yourself homeowners, or retailers on which they rely.
Furthermore, the kit of parts of the '307 patent is adapted for assembly using industrial equipment and custom fixturing. It is critical that sufficient torque be applied when assembling the valve of the '307 patent, particularly since tightening the connection fittings serves two purposes, namely, pre-loading the seals on the ball of the ball valve, and fixing the connection fittings to the valve housing. To satisfactorily pre-load the seals and to seal the brass-to-brass connection between the fitting and the valve body, a relatively high torque is required. This torque is easily reached with power fastening tools and fixtures designed to hold the valve body during tightening, without damaging the valve. However, since a user in the field cannot be expected to have specialized equipment for tightening of the connection fittings, offering the kit of parts of the '307 patent to such a user is of no benefit
Furthermore, factory assembly of the parts of the '307 patent permits leak testing of the valve open/close operation at the factory. Since the assembly of the valve core is completed by assembly of the connection fittings, providing the kit of parts of the '307 patent to a user in the field would eliminate the ability to test the valve operation prior to final installation of the valve.
What is required is a kit of parts from which a valve for connection with any of a wide variety of conduit configurations can be assembled, using ordinary hand tools. The closure member of the valve should be sealed and assembled independatly of the connection fittings to permit factory assembly and leak-testing.
The above and other objects, features, and advantages of the present invention will be apparent in the following detailed description of the preferred embodiment thereof.